Apparatus for producing molded pulp articles



June 4, 1940. Q s g 2,203,343

APPARATUS FOR PRODUCING MOLDED PULP ARTICLES Filed July 24, 193'? 3 Sheets-Sheet 1 June 4, 1940. c. STACK APPARATUS FOR PRODUCING MOLDED PULP ARTICLES Filed July 24, 193? 3 Sheets-Sheet 2 1 H J r I, w I t 3: I

June 4, 1940; Q $TAK 2,203,343

APPARATUS FOR PRODUCING HOLDED PULP ARTICLES Filed July 24, 1937 3 Sheets-Sheet 5 Patented June 4, 1940 UNITED. STATES ArrAaA'rUs roa raonocmomoman I PULP ARTICLES Carl Stack, Gary, Ind.

Application July 24, 1937, Serial No. 155,383

2 Claims.

This invention relates to improvements in apparatus for producing molded pulp articles and it consists of the matters hereinafter described and more particularly pointed out in the appended claims. The apparatus of the present invention contemplates the production of such molded pulp articles as pie plates, cake circles, food trays and the like but may be employed in making other articles, as will be apparent.

One of the objects of the present invention is to provide an apparatus of this kind which is simple in construction and is positive, fast and efllcient in operation.

Another object of the-invention is to provide apparatus of this kind, wherein the molding dies rotate in a horizontal path about a vertical axis, so that the apparatus may be made relatively low in height for easy inspection and servicing when so necessary.

Again, it is an object of the invention to provide apparatus of this kind wherein the articles leave the same with a sharp clean edge due to the fact that all of the periphery of the pick up mold is entered into the pulp material and is withdrawn therefrom at the same time so that there is no back wash of material as occurs in the horizontal drum type of apparatus for a similar purpose.

The above mentioned objects of the invention, as well as others, together with the many advantages thereof will more fully appear as the specification proceeds.

In the drawings:

Fig. 1 is a top plan view of an apparatus for making molded pulp articles embodying the preferred form of the invention.

Fig. 2 is a transverse vertical sectional view through the same as taken on the line 22 of Fig. 1.

Fig. 3 is a detail transverse vertical sectional view on an enlarged scale through one of the mold or die supports of the apparatus and assoc iated parts, the plane of the section being taken on the line 33 of Fig. 1.

Fig. 41s a perspective view of one of the articles produced by the apparatus.

Fig. 5 is a vertical detail sectional view through one of the mold or die supports and associated parts on a further enlarged scale and illustrates a modified form of the invention which will be more fully described later.

Fig. 6 is a perspective view on a reduced scale of a certain cam track providing member embodied in the apparatus and which will be more fully referred to later.

Referring now in detail to that embodiment of the invention illustrated in Figs. 1 to 3 inclusive of the accompanying drawings: I0 indicates as a whole the horizontally disposed base of the machine adapted for engagement upon any suitable kind of support. N indicates an. upright 5 stud or shaft fixed at its bottom end to the central portion of said base. As shown. herein the bottom end of said stud or shaft carries a flange l2 bolted to the'base as at l3. Sleeve ll surrounds the stud or shaft II for rotation about 10 the axis thereof, an antifriction thrust bearing l5 being interposed between the bottom end of said sleeve l4 and the flange l2. About midway between the ends of said sleeve is an outwardly extending radial flange I6.

indicates the horizontal table of the apparatus, disposed a suitable distance above the base and surrounding that portion of the sleeve l4 above the flange l6. Said' table, which is in the form of a circular plate, rests upon and is se- 20 cured to the flange It as by means of bolts l6a.

A bevelled rack I8 is secured to the underside of the table near its periphery. A bevelled driving pinion IS on a shaft 20 meshes with the rack to drive the table continuously in one direc- 25 tion about the axis of the stud or shaft.

Vertical posts or pins 2| are adjustably secured at their bottom ends in the base plate, in arcuately spaced relation on the same circle. The top end of each post or pin is guidingly engaged 30 in an associated recess 22 in the underside of a ring 23, the top surface 'of which has a faced fit against the associated part of the underside of the table. Annular inner and outer packing rings 24 are disposed in coacting grooves in the ring 23 and in the table respectively to provide a running seal between the two.

The posts 2| each support a shoulder or washer 25 and a helical expansion spring 26 surrounds each post between said shoulder and the ring 23. 40 These springs operate jointly to yieldingly hold the said ring in snug engagement with the underside of the table. A nut 21 is threaded on each post 2| to engage the shoulder or washer 25 thereon and by which the tension of each spring 45 may be accurately gauged. A second nut 28 is threaded on each post and whereby the respective posts may be adjusted in height relatively to the base.

In the upper surface of the ring 23 is formed an incomplete circular groove 29 as best appears so in dotted lines in Fig. 1, the ends of the groove being spaced apart by a blank portion 30 of the ring 23. A suction pipe 3| (see Fig. 1) is connected at one end to the groove 29 in said ring, and is connected at its other end to a suction pump 2,203,343 part of the table, to one side of the radial plane (not shown). A pipe 32 (see Fig, 1 for air under pressure, opens upwardly through the blank portion of the ring 23-, radially outward from the circle of the groove 29, as indicated M33.

The table I! carries a plurality of Yarcuately spaced, upright guide posts 34arranged on acircle, outside that of the ring 23. Each post. carries clamp nut' 35. for securing it in position.

with respect to the table. 36,-36 indicate a plurality of mold or'die supports, one, for each post 34 and each including a downwardly facing hollow head 31. Each mold support has associated therewith a vertically depending actuator rod 38.

The top end of each actuator rod extends through its mold support and clamp nuts are operatively threaded on the rod to clamp. against the top and bottom surface of the mold' support.

Each actuator rod has sliding guided bearing in a sleeve 40 provided therefor in the table; The bottom end of each actuator rod is bifurcated to receive a'roller 4I.

0n the'base ill of the apparatus, in the circle of the actuator rods38 "is anincomplete circular cam track 42 shown in perspective in Fig. 6.

The rollers of all of said-actuator rods areadapted to ride around the cam track 42. .It is apparent that in the rotation of the table; themold supports 36 rotate therewith, and' due to the engagement of the rollers 41 with the cam track, will move vertically with a rising and falling action in-accordance with thecontour' of said track.

As shown herein, the hollow head of each mol support carries a perforated forming mold ordie 43 covered by a foraminous sheet such as a piece of fine mesh screen 44. On the table I'I axially in line with each forming mold or.die is aperforated compression die 45, each seated in-a recess 46 in the table. As herein shown, there. isonly one mold or die associated with each support but in practice, it is contemplated thata plurality of such molds or dies 'will be, carried by- I each support, say conveniently four thereof Under such conditions, there will be. four coact-' ing compression dies '45 aligned with each four forming molds or dies 43-. To insure accurate registration between each compression die and its associated and forming" mold or die in therelative movement of said dies toward each other, a plurality ofupright pilot pins 41 are associated with each compression die. As shown herein, the pilot pins are secured in the table about the compression dies. The hollow head 31 of each die support is formed with. openlugs 48' for registration with the pilotpins so that in the relative axial movement between thedie' support and the table, the pins enter said openings. Thus an accurate registration of .each

forming mold or die with an associated compression die is afforded. v

A pair of flexiblet'ubes 50 and 5| respectively, is associated with each forming mold or die, the former being the suction tube and the latter being the pressure tube. One end of the'suction tube is suitablyv connected to the hollow head of the associated supportfwhile the other end of said tube is connected to a nipple 50a secured to the table in the circle of the suction groove 29;

One end of the pressure tube is suitably connected to the hollow head of the associated support while the other end of the tube is connected passing through the air pressure inlet 33, is an open. top jarcuate tank 52 tov hold a supplylof suchan'elevation above, the table that the compression dies '45 and associated pilot'pins 41 may pass; beneath the tank in therotation .of-the table. The tank has a'pulp, material inlet 53 'and ajpulp material outlet 54, the inlet and outlet leading from and to a main source of supply and constituting a part of a pulp materialcirrotation of the table.

' iifindlcates av take ofl conveyorarranged. in

the radial plane of the air-pressure inlet 33 be.-

fore mentioned, in such a manner as to be disposed between the table 11 and the supports v36 when' the latter are in their highest elevation When thesupports 36 moveabove the table. into said' radial plane, the molded pulp article is discharged from the forming mold or die thereof onto the conveyor to be carried thereby through suitable drying means not shown'herein. I'he forming dies 43 and the compressiondies 45 as shown herein are of such formation as to produce-fa conventional molded pulp pie plate,

one of which appears in Fig.4."

Associated with the end 42b of thecam is a. depressed portion 420 :culati'ngsystem, whereby the pulp material in the tank-,isi causedto flow in the direction of: the,

and which controls the projection and theretraction of the forming molds or dies into and out of said tank. 1 m Assume that in the operation of the apparatus I wherein the table I1 and die supports 36 are rotating clockwise, one of'the die supports 36 is f swinging into and through the radial plane of the,

air. pressure inlet 33 before mentioned, at which time it is in a position above the conveyor 55.

When said support 36 is disposed in said plane,

the nipple 51 a associated with the air pressure tube 5| thereof, lines up with the. air pressureinlet 33 in the ring 23 at which time thesuction tube nipple is cut oil from the suction groove 29.

At this time, air under pressure-passes through the tube 5| into the head'3'l, toblow through the forming die and associated screen thereofytp' I discharge a formed but undried pulp'article upon the conveyor 55 for deliveryto thedrying gmeans;

before mentioned. At this time the support is riding at such an elevation on the camtrack as to bring' its die and screen above the plane of the top edge of the tank.

In the further rotation of the tableand the die support,vthe,roller 4| of the actuator rod 40 associated with said die support is riding upon the high side of the cam track but is approaching the cam track depression 420, this-occurring about the time the die support haspassed. ove'rthe conveyor and .is. approaching the inlet end."

of'the tankx52. I y I So soon as the the support clears the inlet end wall of the tank, the roller 4| of its'actuator rod, enters the cam track depression 420. 'Due to gravitational action of the head,-the hollow head associated suction tube 50 registers with the sue- -,of the support descends to dip and submerge its forming mold or'die intothe Pulp material in Y the tank. At this time the inlet nipple 53a of the ao' l The shape and contour of .the'cam' track 42 bestappe rs in Fig. 6.1 -As'shown' therein, the 42b are spaced apart and slope uption groove 29 in the ring 23 so that a suction action develops in the hollow head 31 of the mold support to suck up a quantity of the pulp which is retained on the screen carried by said support. By reason of circulating the pulp material through the tank in the direction, as before described, no splashing or undue turbulence is present as the forming mold or die enters the tank. As the forming mold or die approaches the discharge end of the tank, the roller ll of its associated actuating rod 38 rides up the other side of the depression 420 onto a high spot of the cam track adjacent the cam track end 42b. At this time the mold or die with its charge of pulp fibres upon its screen will have cleared the discharge end of the tank.

Assaid roller travels down said end 4212 of the cam track, it is apparent that through the actuator rod 38, the mold support descends so that the forming mold or die descends therewith to meet the associated compression die 45, the pilot pins 41 and holes 48 assuring registration between said dies. When the two dies are engaged, the roller 4| is in a position between the ends of the cam track and is disposed a slight distance above and out of contact with the base l3. By reason of the weight of the die support and associated parts, the forming mold or die operates in conjunction with the compression die to impart a squeezing pressure upon the fibres disposed upon the screen of the forming mold or die to compress said fibres and form the article.

This gives the article a better and smoother appearance and extracts as much of the water content from the formed article, as is possible.

As the roller ll of the associated actuating rod engages and rides up the inclined end 42a of the cam track, the mold support rises in accordance with the inclination of said end, the partly formed article being held in place upon the forming mold or die by suction. This suction continues to extract water until the article is ready to be discharged onto the conveyor. When said die support reaches the position above the conveyor, before mentioned, the nipple 50a moves onto the blank space between the ends of the groove 29 in the ring 23 and the nipple Sla registers with the air pressure inlet 33 so that a blast of air is discharged through the hollow head of the mold support to loosen the formed article for depositing the same upon the conveyor for discharge.

It is apparent that the operation of the die members occurs in succession so that the apparatus is continuous in its operation of producing articles.

In Fig. is illustrated a slightly modified form 'of construction directly associated with the forming mold or die to provide a pressure for urging the same into a moreintimate contact with its associated compression die. Such a construction which is located in aradial plane between the ends 42a--l2b of the cam track, comprises an upright bracket 60 secured to the base I0, outside the periphery of the table. Said bracket has a laterally extending arm H at the top that is disposed in a plane above the top of the die supports as they pass beneath the same so as to overhang a portion thereof. Slidable in said arm in'the circle of the axis of the dies, as they pass beneath said arm, is a spring pressed plunger 32. The bottom end of this plunger is bifurcated to receive a roller 63 which engages with a top portion of the support 36 as the same passes under the same. The opposite sides of the support have laterally extending inclined surface portions 64 upon which the roller rides as the support passes under the same. As the roller rolls up the advancing surface portion 64, this compresses the spring, which imparts its pressure to the support to force the forming mold or die on said support into intimate compression engagement with the compression die. As the support passes beneath the roller, the roller moves downward upon a trailing surface portion on the opposite side of the support and off the same to release the pressure from the support. This action is repeated each time a support passes beneath the roller.

The apparatus is simple in construction and 'is positive and fast in operation.

While in describing the invention, I have referred in detail to the form, arrangement and construction of the parts involved, the same is to be considered only in the illustrative sense so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention:

1. Apparatus for producing molded paper pulp articles, means providing a support, means providing a horizontal member rotatably mounted on said support, a plurality of compression dies rigidly mounted on the upper surface of said rotatable member, a plurality of forming dies arranged above said rotatable member, each of thelast mentioned dies including a die carrying head and a lateral extension, a plurality of upright guide posts on said rotatable member, one for each forming die and each passing through the lateral extension thereof and having a sliding engagement therewith, an actuator rod fixed to each forming die and having a sliding bearing engagement through the rotatable member, said actuator rod supporting the forming die, antifriction means on the lower end of the actuator rod, and an incomplete cam mounted on the support beneath the rotatable member and adapted to be traversed by the anti-friction means on the lower end of the actuator rod, whereby the forming die is adapted to fall by gravity into engagement with the compression die to compress the article therein.

2. Apparatus for producing molded paper pulp articles, means providing a support, means providing a horizontal member rotatably mounted on said support, a plurality of compression dies rigidly mounted on the upper surface of said rotatable member, a plurality of forming dies arranged above said rotatable member, each of the last. mentioned dies including a die carrying head and a lateral extension, a plurality of upright guide posts on saidrotatable member, one for each forming die and each passing through the lateral extension thereof and having a sliding engagement therewith, an actuator rod fixed to each forming die and having a sliding bearing engagement through .the rotatable member, said actuator rod supporting the forming die, anti-friction means on the lower end of the actuator rod, an incomplete cam mounted on the support beneath the' rotatable member and adapted to be traversed by the anti-friction means on the lower end of the actuator rod, whereby the forming die is adapted to fall by gravity into engagement with the compression die to compress the article therein, and means engaging the head for imparting additional pressure on the forming die.

CARL STACK. 

